Lightning detector



FIG. 1 is an elevated frontal perspective view of our new design for a lightning detector;

FIG. 2 is a bottom side perspective view thereof;

FIG. 3 is an elevated right side view thereof, the left side being identical;

FIG. 4 is an elevated front end view thereof, the back end view being identical;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in the drawing illustrate portions of the lightning detector that form no part of the claimed design. 

CLAIM The ornamental design for a lightning detector, as shown and described. 